Medicaments frequently are administered to the eye for the treatment of ocular diseases and disorders. Conventional means for delivering medicaments to the eye involve topical application to the surface of the eye. The eye is uniquely suited to topical administration because, when properly constituted, topically applied medicaments can penetrate through the cornea and rise to therapeutic concentration levels inside the eye. Medicaments for ocular diseases and disorders may be administered orally or by injection, but such administration routes are disadvantageous in that, in oral administration, the active agent may reach the eye in too low a concentration to have the desired pharmacological effect and their use is complicated by significant, systemic side effects and injections pose the risk of infection.
The majority of ocular medicaments are currently delivered topically using eye drops which, though effective for some applications, are inefficient. When a drop of liquid is added to the eye, it overfills the conjunctival sac, the pocket between the eye and the lids, causing a substantial portion of the drop to be lost due to overflow of the lid margin onto the cheek. In addition, a substantial portion of the drop that remains on the ocular surface is drained into the lacrimal puncta, diluting the concentration of the drug.
Other methods allow for the eluding of a medicament over a period of time. However, some medicaments are most efficacious when periodically delivered in a predetermined dosed amount. Accordingly, alternative methods and devices for delivering medicaments to an ophthalmic area may be beneficial.